In a large saucepan bring half the coconut milk to a boil and heat, stirring, until it separates.
Add the red curry paste and cook until fragrant. Add the fish sauce and sugar and continue to cook for a few moments.

Stir in the rest of the coconut milk and bring back to a boil. Add the jumbo shrimp, mussels, pineapple and lime juice.

Reheat until boiling and then simmer for 3-5 minutes, until the shrimp are cooked and the mussels have opened. Remove any mussels that have not opened and discard. Serve garnished with chopped red chilies and cilantro. Makes 4-6 servings.